NAME

crash − examine system images

SYNOPSIS

/etc/crash [ −d dumpfile ] [ −n namelist ] [ −w outputfile ]

DESCRIPTION

The crash command is used to examine the system memory image of a live or a crashed system by formatting and printing control structures, tables, and other information.  Command line arguments to crash are dumpfile, namelist, and outputfile. 

dumpfile is the file containing the system memory image.  The default dumpfile is /dev/mem. 

The text file namelist contains the symbol table information needed for symbolic access to the system memory image to be examined.  The default namelist is /unix.  If a system image from another machine is to be examined, the corresponding text file must be copied from that machine. 

When the crash command is invoked, a session is initiated.  The output from a crash session is directed to outputfile.  The default outputfile is the standard output. 

Input during a crash session is of the form:

function [argument ... ]

where function is one of the crash functions described in the FUNCTIONS section of this manual page, and arguments are qualifying data that indicate which items of the system image are to be printed. 

The default for process-related items is the current process for a running system and the process that was running at the time of the crash for a crashed system.  If the contents of a table are being dumped, the default is all active table entries. 

The following function options are available to crash functions wherever they are semantically valid. 

−e Display every entry in a table. 

−f Display the full structure. 

−p Interpret all address arguments in the command line as physical addresses. 

−s process
Specify a process slot other than the default.

−w file
Redirect the output of a function to file. 

Note that if the −p option is used, all address and symbol arguments explicitly entered on the command line will be interpreted as physical addresses.  If they are not physical addresses, results will be inconsistent. 

The functions mode, defproc, and redirect correspond to the function options −p, −s, and −w.  The mode function may be used to set the address translation mode to physical or virtual for all subsequently entered functions; defproc sets the value of the process slot argument for subsequent functions; and redirect redirects all subsequent output. 

Output from crash functions may be piped to another program in the following way:

function [argument ... ]!shell_command

For example,

mount ! grep rw

will write all mount table entries with an rw flag to the standard output.  The redirection option (−w) cannot be used with this feature. 

Depending on the context of the function, numeric arguments will be assumed to be in a specific radix.  Counts are assumed to be decimal.  Addresses are always hexadecimal.  Table slot arguments are always decimal.  Table slot arguments larger than the size of the function table will not be interpreted correctly.  Use the findslot command to translate from an address to a table slot number.  Default bases on all arguments may be overridden.  The C conventions for designating the bases of numbers are recognized.  A number that is usually interpreted as decimal will be interpreted as hexadecimal if it is preceded by 0x and as octal if it is preceded by 0.  Decimal override is designated by 0d, and binary by 0b. 

Aliases for functions may be any uniquely identifiable initial substring of the function name.  Traditional aliases of one letter, such as p for proc, remain valid. 

Many functions accept different forms of entry for the same argument.  Requests for table information will accept a table entry number or a range.  A range of slot numbers may be specified in the form a−b where a and b are decimal numbers.  An expression consists of two operands and an operator.  An operand may be an address, a symbol, or a number; the operator may be +, −, *, /, &, or | .  An operand which is a number should be preceded by a radix prefix if it is not a decimal number (0 for octal, 0x for hexadecimal, 0b for binary).  The expression must be enclosed in parentheses (). Other functions will accept any of these argument forms that are meaningful.

Two abbreviated arguments to crash functions are used throughout.  Both accept data entered in several forms.  They may be expanded into the following:

table_entry = table entry| range

start_addr = address| symbol| expression

FUNCTIONS

? [−w file]
List available functions.

!cmd Escape to the shell to execute a command. 

adv [−e] [−w file] [[−p]table_entry...]
Print the advertised table.

base [−w file] number ...
Print number in binary, octal, decimal, and hexadecimal.  A number in a radix other than decimal should be preceded by a prefix that indicates its radix as follows: 0x, hexadecimal; 0, octal; and 0b, binary. 

buffer [−w file] [−format] bufferslot

or

buffer [−w file] [−format] [−p]start_addr
Alias: b. 
Print the contents of a buffer in the designated format. The following format designations are recognized: −b, byte: −c, character; −d, decimal; −x, hexadecimal; −o, octal; −r, directory; and −i, inode.  If no format is given, the previous format is used.  The default format at the beginning of a crash session is hexadecimal. 

bufhdr [−f] [−w file] [[−p]table_entry...]
Alias: buf. 
Print system buffer headers.

callout [−w file]
Alias: c. 
Print the callout table.

dballoc [−w file] [class ... ]
Print the dballoc table. If a class is entered, only data block allocation information for that class will be printed.

dbfree  [−w file] [class ... ]
Print free streams data block headers. If a class is entered, only data block headers for the class specified will be printed.

dblock [−e] [−w file] [−c class...]

or

dblock [−e] [−w file] [[−p] table_entry...]
Print allocated streams data block headers. If the class option (−c) is used, only data block headers for the class specified will be printed. 

defproc [−w file] [−c]

or

defproc [−w file] [slot]
Set the value of the process slot argument. The process slot argument may be set to the current slot number (−c) or the slot number may be specified.  If no argument is entered, the value of the previously set slot number is printed.  At the start of a crash session, the process slot is set to the current process. 

dis [−w file] [−a] start_addr [count]
Disassemble from the start address for count instructions.  The default count is 1.  The absolute option (−a) specifies a non-symbolic disassembly. 

ds [−w file] virtual_address ...
Print the data symbol whose address is closest to, but not greater than, the address entered.

file [−e] [−w file] [[−p]table_entry...]
Alias: f. 
Print the file table.

findaddr [−w file] table slot
Print the address of slot in table.  Only tables available to the size function are available to findaddr. 

findslot [−w file] virtual_address ...
Print the table, entry slot number, and offset for the address entered. Only tables available to the size function are available to findslot. 

fs [−w file] [[−p]table_entry...]
Print the file system information table.

gdp [−e] [−f] [−w file] [[−p]table_entry...]
Print the gift descriptor protocol table.

gdt [−e] [−w file] [[−p] table_entry...]
Print the global descriptor table.

help [−w file] function ...
Print a description of the named function, including syntax and aliases.

idt [−e] [−w file] [[−p]table_entry...]
Print the interrupt descriptor table.

inode [−e] [−f] [−w file] [[−p]table_entry...]
Alias: i. 
Print the inode table, including file system switch information.

kfp [−w file] [value]
Print the frame pointer for the start of a kernel stack trace.  If the value argument is supplied, the kfp is set to that value.

lck [−e] [−w file] [[−p]table_entry...]
Alias: l. 
Print record-locking information. If the −e option is used or table address arguments are given, the record lock list is printed.  If no argument is entered, information on locks relative to inodes is printed. 

ldt [−e] [−w file] [-s process] [[−p]table_entry...]
Print the local descriptor table for the given process, or for the current process if none is given.

linkblk [−e] [−w file] [[−p]table_entry...]
Print the linkblk table.

map [−w file] mapname ...
Print the map structure of mapname, e.g., sptmap, piomap, etc. swap and core are not valid map symbols. 

mbfree [−w file]
Print free streams message block headers.

mblock [−e] [−w filename] [[−p]table_entry...]
Print allocated streams message block headers.

mode [−w file] [mode]
Set address translation of arguments to virtual (v) or physical (p) mode.  If no mode argument is given, the current mode is printed.  At the start of a crash session, the mode is virtual. 

mount [−e] [−w file] [[−p]table_entry...]
Alias: m. 
Print the mount table.

nm [−w file] symbol ...
Print value and type for the given symbol.

od [−p] [−w file] [−format] [−mode] [−s process] start_addr

[count]
Alias: rd. 
Print count values starting at the start address in one of the following formats:  character (−c), decimal (−d), hexadecimal (−x), octal (−o), ASCII (−a), or hexadecimal/character (−h), and one of the following modes: long (−l), short (−t), or byte (−b).  The default mode for character and ASCII formats is byte; the default mode for decimal, hexadecimal, and octal formats is long.  The format −h prints both hexadecimal and character representations of the addresses dumped; no mode needs to be specified.  When format or mode is omitted, the previous value is used.  At the start of a crash session, the format is hexadecimal and the mode is long.  If no count is entered, 1 is assumed. 

panic
Print the latest system notices, warnings, and panic messages from the limited circular buffer kept in memory.

pcb [−w file] [process]
Print the process control block (TSS) for the given process.  If no arguments are given, the active TSS for the current process is printed.

pdt [−e] [−w file] [−s process] [−p] start_addr [count]
The page descriptor table of the designated memory section and segment is printed.  Alternatively, the page descriptor table starting at the start address for count entries is printed.  If no count is entered, 1 is assumed. 

pfdat [−e] [−w file] [[−p]table_entry...]
Print the pfdata table.

proc [−e] [−f] [−w file] [[−p] table_entry ... #procid ...]

or

proc [−f] [−w file] [−r]
Alias: p. 
Print the process table. Process table information may be specified in two ways. First, any mixture of table entries and process ids may be entered. Each process id must be preceded by a #.  Alternatively, process table information for executable processes may be specified with the executable option (−r).  The full option (−f) details most of the information in the process table as well as the region table for that process.  In the process table output, size=### is the number of pages of memory that the current process is using. 

qrun [−w file]
Print the list of scheduled streams queues.

queue [−e] [−w file] [[−p]table_entry...]
Print streams queues.

quit Alias: q. 
Terminate the crash session. 

rcvd [−e] [−f] [−w file] [[−p]table_entry...]
Print the receive descriptor table.

redirect [−w file] [−c]

or

redirect [−w file] [file]
Used with a file name, redirects output of a crash session to the named file.  If no argument is given, the file name to which output is being redirected is printed.  Alternatively, the close option (−c) closes the previously set file and redirects output to the standard output. 

region [−e] [−w file] [[−p]table_entry...]
Print the region table.

sdt [−e] [−w file] [−s process] section

or

sdt [−e] [−w file] [−s process] [−p] start_addr[count]
The segment descriptor table for the current process is printed.

search [−p] [−w file] [−m mask] [−s process]

pattern start_addr count
Print the long words in memory that match pattern, beginning at the start address for count long words.  The mask is anded (&) with each memory word and the result compared against the pattern.  The mask defaults to 0xffffffff. 

size [−w file] [−x] [structure_name ... ]
Print the size of the designated structure.  The (−x) option prints the size in hexadecimal.  If no argument is given, a list of the structure names for which sizes are available is printed. 

sndd [−e] [−f] [−w file] [[−p]table_entry...]
Print the send descriptor table.

srmount [−e] [−w file] [[−p]table_entry...]
Print the server mount table.

stack [−w file] [process]
Alias:  s. 
Dump stack. If no arguments are entered, the kernel stack for the current process is printed. The interrupt stack and the stack for the current process are not available on a running system.

stat [−w file]
Print system statistics.

stream [−e] [−f] [−w file] [[−p]table_entry...]
Print the streams table.

strstat [−w file]
Print streams statistics.

trace [−w file] [−r] [process]
Alias: t. 
Print kernel stack trace.  The kfp value is used with the −r option. 

ts [−w file] virtual_address ...
Print closest text symbol to the designated address.

tty [−e] [−f] [−w file] [−ttype[[−p]table_entry...]]
Valid types: co, c1, c2 (console, com1, com2). 
Print the tty table. If no arguments are given, the tty table for the console is printed. If the −t option is used, the table for the single tty type specified is printed.  If no argument follows the type option, all entries in the table are printed.  A single tty entry may be specified from the start address. 

user [−f] [−w file] [process]
Alias: u. 
Print the ublock for the designated process.

var [−w file]
Alias: v. 
Print the tunable system parameters.

vtop [−w file] [−s process] start_addr...
Print the physical address translation of the virtual start address.

FILES

/dev/mem         system image of currently running system

ADDED VALUE

This entry, supplied by SunSoft, Inc., contains enhancements to UNIX System V. 

\*U  —  Version 1.0